Interactive systems and their human being-machine-interfaces are known for the human being-computer-interaction, wherein the human being-machine-interfaces are provided with a device for the automatic recognition of non-tactile or tactile gestures performed by human beings. The gesture can principally be derived from every posture and every movement of the body. The gesture recognition device is provided with a device for the acquisition of the gesture, wherein the image information generated thereby is processed with corresponding algorithms in order to derive a gesture out of the information. For example, a mobile telephone is conventionally provided with the gesture recognition device such that with the gesture recognition device it can be detected if the mobile telephone is held at the head of a human being in order to activate, respectively deactivate an associated function of the mobile telephone for telephoning. The gesture recognition device of the mobile telephone for recognizing the presence of the human head is conventionally based on the optical acquisition of the surroundings of the mobile telephone, wherein the presence of the head is considered to be detected as soon as the head is optically acquired by the gesture recognition device. It is hereby to be taken into account that the human head is supposed to be distinguished from other human body parts approaching the mobile telephone, wherein disturbing influences from the surroundings, for example a change of the light conditions, have to be masked out. Further, it is difficult to provide the gesture recognition such that the accuracy during the detection of the presence of the human head is not influenced if the human being wears a cap or a hat or which haircut the human being has, in particular if the human being has long hair or is bald.